. >> reporter: secretary clinton said the missile shield will only be used for defensive purposes. nato did not discuss a no fly zone or safe haven to protect syrians. for "cbs this morning," margaret brennan, nato headquarters, brussels. >>> in an interview on tuesday, i asked former defense secretary robert gates about the worsening situation in syria and the possibility of the government using chemical weapons against the rebels. >> what should we do in syria if they attempt to move the chemical weapons? >> well, i think that based on what the president has said, we would have no alternative to some kind of military response. and then there are a range of possibilities, but i think -- the one thing about when -- we use this expression more than once. when the president of the united states cocks the pistol, he better be ready to fire it. so a warning of that kind must have consequences if something happens with those chemical weapons. but he has a wide range, i think, of options in that event. >> based on everything you know about this president, is he prepared? >> oh, yeah. no,